Commutator-brush holder



(No Model.)

R. HIRSGH.

I GOMMUTATOR BRUSH HOLDER.

Patented Apr. '7, 1896.

LII

UNITED STATES PATENT OFFICE.

ROBERT IIIRSOI'I, OF MILIVAUKEE, IVISCONSIN.

COMMUTATOR-BRUSH HOLDER.

SPECIFICATION forming part of Letters Patent N 0. 557,678, dated April'7, 1896. Application filed July 1, 1895. Serial No. 554,612. (Nomodel.)

To aZZ whom it may concern.-

Be it known thatLRoBEET I-Imsorna citizen of the United States, residingat Milwaukee, county of Milwaukee, State of \Visconsin, have invented acertain new and useful Improvement in commutator-Brush Holders; and Ideclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itpertains to make and use the same, reference being had to theaccompanying drawings, which form a part of this specification.

My invention relates to new and useful improvements in the constructionof brush-holders for dynamo-electric machines and motors; and itconsists in the matters hereinafter described, and pointed out in theappended claims.

I11 the accompanying drawings, illustrating my invention, Figure 1 is aview, partly in elevation and partly in section, on line 1 1 of Fig. 2.Fig. 2 is a transverse sectional view of the same, taken on line 2 2 ofFig. 1. Fig. 3 is a cross-sectional view taken on line 3 3 of Fig. 1.Fig. etis a detail view, partlyin elevation and partly in section, 011line 4: 4 of Fig. 1.

Referring by letter to the drawings, A designates the commutator of adynamo-electric machine or motor, and B one of the usual supports whichproject from the frame of the machine and are arranged to support thebrushes or collectors in operative position adjacent to the commutator.In the accompanying drawings only one of these supports is shown and oneholder and brush for engagement with the commutator; but it will ofcourse be understood that two or more supports, with a cor respondingnumber of holders and brushes, will be employed, as the case mayrequire. A block 0 is adjustably secured to the support B in any desiredmanner, conveniently by means of the set-screw C, and to this block issecured a suitable device for pressing the brush against the surface ofthe commutator and also suitable means for regulating the pressure ofthe brush against the commutator.

In practice I find it convenient to employ substantially the form ofconstruction shown in the drawings, in which an arm or plate D issuitably pivoted to the block 0 or a connected part and is acted upon bya spring D in the manner shown. A suitable arm or push-bar E is pivotedat one end, as at e, to the arm or plate D and is arranged to engage inany convenient manner at its free end with 5 5 the rear end of thebrush, so as to press said brush longitudinally toward the surface ofthe commutator.

As shown in the drawings, an extension F is provided upon the block 0,and one face of this extension is arranged in line with the desiredposition of the commutator-brush G, and said brush is arranged to restat one side against said face of the extension F. Arearwardly-projecting lip g is provided upon the rear end of the brush Gfor engagement with the forward end of the arm or bar E, and a suitablespring E is engaged in any convenient manner with said arm or bar E andwith the arm or plate D, to which the arm E is pivoted, and serves tonormally press the free end of said arm E toward the face of theextension F of the block 0, so as to cause said arm E to hold the rearend of the brush G in firm cont-act with the surface of said eXtension.

As shown more particularly in Figs. 1 and 2 of the drawings, the springD has an engagement at one end, as at (Z, with the extension F and atits free end has an adjustable 8o engagement with the arm or plate D bymeans of a number of pins 61 (Z, projecting from the face of said arm orplate D, and against which the free end of said spring is arranged tobear. By this arrangement the pressure or tension of the spring D may bereadily adjusted, so as to regulate the forward pressure of the arm orplate D and produce any desired pressure or tension of the brush-againstthe surface of the commutator.

In the particular form of construction shown in the drawings theextension F upon the block 0 is formed by a separate plate, which hasupon one side a suitable dovetail tongue f, which is movably engagedwith a correspondingly-shaped recess in a block II, which is locatedwithin a recess h in the lower part of the block C. A channel II isformed in the block C at the front and rear of the recess h for thereception of the tongue or rib f. IOO

From the upper side of the block H extends a screw-threaded stud 7b,with the outside of which is engaged a nut H and a washer or plate Ilocated beneath said nut serves as a support or bearing for the same.This separate plate forms the means for connecting the arm or plate Dwith the support, and said plate F, together with the arm or plate D,and the push-bar E being thus connected together are of courseadjustable together upon the support. By this means the plate F isrendered adjustable longitudinally toward or from the commutator, andwhen adjusted may be securely retained in position by the nut H in anobvious manner.

As shown more particularly in Fig. 4, I prefer to construct the arm Ewith laterally-extending projections c e at its free end, togetherforming a transverse bar, and this bar is preferably beveled upon bothsides, as shown in Fig. 1, and provided with teeth 6 e in the mannershown in Fig. 4. 3y this means a secure engagement is afforded betweenthe end of the arm E and the rear end of the brush G, and the liabilityof the brush shifting or slipping laterally is prevented.

It follows from the foregoing construction that by means of the pivotedarm or plate D and the connected arm E the brush G, when in operativeposition, will be automatically pressed forward into electrical contactwith the surface of the commutator, and that as fast as said brushbecomes worn said arms will be automatically adjusted by the spring D soas to compensate for the wear upon the front end of the brush.

By the described construction the plate F may be readily adjusted towardor away from the commutator so as to rest at a desired distance from thesurface thereof, and in case said commutator becomes worn said plate maybe adjusted forward to compensate for said wear. By this construct-ionthe holder may be adjusted so as to adapt it for use upon differentmachines without the necessity of fitting or filing the holder.

Furthermore, by the described construction the upper surface of thebrush is maintained in constant electrical contact with the under sideof the plate F, while being at the same time entirely free to movelongitudinally in order to preserve its electrical. contact with thesurface of the commutator.

I'Ieretofore in the construction of commutator-brush holders it has beencommon to provide means for automatically advancing the brush as itbecomes worn; but in such constructions the brushes have usually beenfitted within sockets, and this results in a considerable amount ofwaste of the brushes, from the fact that when they have become worn downto a certain length or size they must be taken out and thrown away,because they can no longer be held in proper position and maintained inproper electrical contact with the commutator. By my improvedconstruction, however, the brush is held only at one end by the holder,and the commutator, rotating in the direction indicated by the arrow inFig. 1, assists in holding the brush in electrical contact with the faceof the plate F.

By means of my improved holder the brush will be held in firm electricalcontact with the surface of the commutator until it has become almostentirely used up, and thereby any appreciable waste of the brushmaterial is obviated.

If desired, my improved brush-holder may be provided with a suitablelatch or detent J, as indicated in Fig. 1 by the dotted lines, whichlatch or detent is pivoted to the plate D, as at j, and is provided atits free end with a notch j, adapted for engagement with a slot 6 111the arm E, whereby the plate D and the arm E may be held in theirretracted positions when desired.

As also indicated by the dotted lines in Fig. 1, suitable upturned lipsor flanges g may be provided upon the rear end of the brush and arrangedto engage behind the projections e of the arm E, so that when the plateD and arm E are retracted the brush will be simultaneously retracted andheld out of contact with the commutator by said arm E.

By my improvement I am enabled to provide a very satisfactory form ofbrush-holder, which while admitting of a very wide range of adjustmentis very sensitive, and at the same time serves to preserve a perfectelectrical contact of the brush both with the holder and with thecommutator.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent of the United States, is-

1. The herein-described brush-holder, comprising a suitable supporthaving a plane surface in line with the desired position of the brush, aspring-controlled arm or plate pivoted at one end to said support, and asecond spring-controlled arm pivotally connected at one end with thefree end of the first-mentioned arm or plate and adapted to bear at itsfree end against the rear end of the brush so as to press the latterinto electrical contact with the surface of said support, and to pressits forward end into electrical contact with an adjacent commutator,substantially as described.

2. The herein-described brush-holder comprising a suitable supporthaving one surface in line with the desired position of the brush, anarm. or plate pivoted at one end to said support and provided with aplurality of lateral projections, a spring engaged at one end. with saidsupport, and adapted for engagement at its other end with a desired oneof said projections, and a second spring-com trolled arm pivotallyengaged at one end with the firs t-mentioned arm or plate, and adaptedto hear at its free end against the rear end of a commutator-brush, tohold said brush in electrical contact with the face of said sup- IIOport, and to press the forward end of said brush into electrical contactwith an adjacent commutator, substantially as described.

3. The herein-described brush-holder comprising a suitable support, aplate adjustably engaged therewith, and having one face arranged in linewith the desired position of the brush, a spring-controlled arm or platepivotally connected at one end with said adjustable plate, and a secondspring-controlled arm pivoted at one end to the free end of thefirstmentioned arm or plate, and adapted to hear at its free end againstthe rear end of a commutator-brush, substantially as and for the purposedescribed.

4:. The herein-described brush-holder comprising the support O, theadjustable plate F, the arm or plate D, pivoted to said plate F, andprovided with the studs or projections d d, the spring D, and thespring-controlled arm E, all constructed and arranged and adapted tooperate substantially in the man ner and for the purpose described.

5. The combination with a brush-holder comprising a support having aplane surface in line with the desired position of the brush, and aspring-actuated follower for engagement with the brush of thecommutator-brush provided upon its rear end with one or more angularprojections or flanges for engagement with the follower to retract thebrush, sub stantially as described.

In testimony whereof I sign this specification in the presence of twoWitnesses.

ROBERT HIRSCH.

itnesses:

J OHN E. WILEs, CHARLES A. KLAVITER.

